You can see the standard bias setting on the picture of my stuffed PCB above. I stuffed the jumper on the left side.

ah, i (think i) know what you mean now. That bias jumper is marked well on the silkscreen of the v1.1 PCB and explained on cgs site. That picture I used is just older. Updated in the original post / redrew to look like the v1.1 now.

LED's are very noisy. Since the cathode is in the signal path, I eliminated the two signal diodes, the two LED's, and their 1.5K resistors.

This comment has being bugging me for a while. LEDs are frequently used as voltage references, and recently I saw one recommended for a reference in a critical application. A little poking around led me to this http://www.diyaudio.com/forums/parts/35821-some-noise-measurements-leds-zener-diodes-post417008.html#post417008 which you need to log in to see, but the gist of it is common red and orange LEDs are only up to 2 times as noisy as a forward biased low-noise transistor or a 1N4148. That isn't very noisy. We are looking at around 0.25 to 0.35 uV. Green isn't as good. Blue is awful at 3.2 uV (10 times as much).

You cannot post new topics in this forumYou cannot reply to topics in this forumYou cannot edit your posts in this forumYou cannot delete your posts in this forumYou cannot vote in polls in this forumYou cannot attach files in this forumYou can download files in this forum

Please support our site. If you click through and buy from our affiliate partners, we earn a small commission.